ICE3RBR0665JG Datasheet, PDF (10/32 Pages) Infineon Technologies AG – Fixed-Frequency, 650V CoolSET™ in DS0-12 Package

Fixed-Frequency, 650V CoolSET™ in DS0-12 Package
Functional Description
When the VVCC exceeds the on-threshold voltage, the IC starts the Soft Start mode (Figure 11).
The function is realized by an internal Soft Start resistor, a current sink and a counter. And the amplitude of the
current sink is controlled by the counter (Figure 12).
5V
SoftS
RSoftS
Soft Start ^{32I 8I 4I 2I I}
Counter
Figure 12 Soft Start Circuit
After the IC is switched on, the VSOFTS voltage is controlled such that the voltage is increased step-wisely (32
steps) with the increase of the counts. The Soft Start counter would send a signal to the current sink control in
every 600 µs such that the current sink decrease gradually and the duty ratio of the gate drive increases
gradually. The Soft Start will be finished in 20 ms (TSoft-Start) after the IC is switched on. At the end of the Soft Start
period, the current sink is switched off.
V_SoftS
VSOFTS32
t_Soft-Start
Gate
t
Driver
t
Figure 13 Gate drive signal under Soft-Start Phase
Within the soft start period, the duty cycle is increasing from zero to maximum gradually (Figure 13).
In addition to Start-Up, Soft-Start is also activated at each restart attempt during Auto Restart
Data Sheet
10
Revision 1.0
2016-05-12